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Home , Ice Harbor Dam, Little Goose Dam, Lower Granite Dam, Lower Monumental Dam, Snake River

Fact Sheet

Fact Sheet

Fact Sheet Fact Sheet Fact Sheet

Fact Sheet

BONNEVILLEFact Sh ePOWERet ADMINISTRATION

Fact Sheet March 2010 Power benefits of the lower In the 1960s and early 1970s, the federal government significantly more power capacity than a typical built four large dams on the Snake River. This is the coal plant. The nameplate capacity of the four lower last set of major dams to have been built in the Federal Snake River dams is as follows: Power System. The FCRPS is the Ice Harbor 603 MW largest source of electricity in the and 810 MW the largest source of renewable electricity in the nation. 810 MW 810 MW The U.S. Army Corps of Engineers owns and operates Total 3,033 MW1 the lower Snake River dams. All four of these dams are In comparison: multiple-use facilities that provide navigation, hydropower, Boardman coal plant 530 MW recreation, and fish and wildlife conservation benefits. These dams were not built to control floods. The four lower Snake River dams can operate above their rated capacity to produce up to 3,483 MW for Because of their location, size and ability to help meet several hours. In an extended cold-snap or other power peak power loads, these four dams do much more than emergency, such as another power plant shutting generate energy. They are key to keeping the system down unexpectedly, these four dams can produce in reliable and helping to meet its multiple uses — including excess of 2,650 MW over a sustained period of 10 hours supporting wind energy. per day for five consecutive days. An important part of the According to the Northwest Power and Conservation Northwest’s power supply Council, capacity is becoming increasingly important to The useful output of a power station is measured in the Pacific Northwest to meet peak loads in the two ways — capacity and energy. The four lower summer as well as the winter. Snake River dams are major power plants by either Much of the year, BPA relies on the four lower Snake measure. River dams specifically to help meet peak loads. This Capacity to meet peak loads ability to produce power when the system needs it most is crucial to maintaining a reliable power supply. Peak capacity typically refers to a power plant’s value in meeting peak power loads. It is the largest amount of 1 For another reference point, the combined capacity of power a plant can generate operating at full capacity. Pacificorp’s seven dams on the Klamath River is 183 MW. Each of the four lower Snake River dams provides (Source: Pacificorp relicensing application to Federal Energy Regulatory Commission.) Energy comparable to 27 years of conservation Average energy is the annual output of a power plant divided by the 8,760 hours of the year. The four lower Snake River dams produce almost as much annual average megawatts as BPA’s conservation programs have achieved in 27 years — at an investment of more than $2.3 billion:

Four lower Snake River dams: ...... 1,022 aMW — capacity 603 MW, energized 1961 BPA conservation programs (1982–2008). . . . 1,190 aMW

Together, the four Snake River dams supply 12 percent A 2007 Council study on the Northwest’s carbon of the average energy production of the entire FCRPS footprint concluded2 that: and 5 percent of the Pacific Northwest. This is enough “Removal of the lower Snake River dams will not energy to serve a city about the size of Seattle. make additional CO2-free energy resources available to meet future load growth or retire any existing “Given the difficulty of reducing coal plants. More than 1,000 MW of emission-free generation eventually will have to be replaced unless CO2 emissions, discarding existing the supplies of renewables and conservation are considered unlimited. Given the difficulty of reducing CO2-free power sources has to be CO2 emissions, discarding existing CO2-free power considered counterproductive.” sources has to be considered counterproductive.” — Northwest Power and Conservation Council These dams keep the system in balance Emission-free renewable energy While BPA markets power from 31 federal dams, only the 10 largest dams keep the federal power system Hydropower is a renewable resource and produces operating reliably through Automatic Generation virtually no greenhouse gas emissions. Control. Four of these 10 dams are lower Snake River Replacing the power from the four lower Snake River projects. dams results in increased carbon emissions of 3.0 million Under AGC, when total generation in the power tons year, according to the Council’s Sixth Power Plan. system differs from total load being consumed, This is an amount five times greater than the amount of automatic signals go to these few dams to increase carbon saved by renewable resource standards or decrease generation. This maintains the constant adopted by the states of , and balance of generation and loads necessary for power combined. system reliability.

Of the other dams on AGC, and Chief Joseph Dam are on the Columbia River above its with the Snake River. The other four are on the lower river, below the Snake River confluence.

2 Northwest Power and Conservation Council, “Carbon Dioxide Footprint of the Northwest Power System” (Nov. 2007), p. 11.

Lower Granite Dam — capacity 810 MW, energized 1975

2 Streamflows in the Snake and upper Columbia River often differ. When one river’s use is particularly constrained, the other may be used more to help meet the total fish, power, flood control and other needs. (During and summer, the AGC capability of the lower Snake River dams is limited by the requirements of fish operations at these dams.) Snake River dams contribute to transmission system reliability Lower Monumental Dam — capacity 810 MW, energized 1969 The lower Snake River dams are integrated into the transmission grid by a long 500-kilovolt transmission Absent generation at these projects, the carrying line that runs from western Montana to eastern capability of certain major transmission lines would Washington. Other generators are also connected on have to be reduced. this transmission path. Hydro’s flexibility helps support

The lower Snake River dams provide necessary voltage wind power r

regulation on this long transmission path, keeping the e v Windi is booming in the BPA transmission grid. Today, system reliable. R

a the i agency expects to see about 6,000 MW on line by b

m Similarly, because the Snake RiverBRITIS damsH CO lieLUMBIA east of 2013,u which is expected to give BPA the highest ratio l

o the other federal generators, they provide a significant of Cwind power to load of any power system in the technical contribution to transmission grid reliability. .

Because wind power is Automatic Generation Control on federal damsBoundary variable, it must be complementedHungry with other Libby Horse Chief generation that can be

Joseph Cabinet Gorge n increased when wind Wells Albeni Noxon Rapids

a Grand Falls unexpectedly dies down Seattle Coulee

e Rocky or decreasedKerr when the Reach Spokane

c Rock Island wind blows harder. WA SH IN GT ON MONTAN A O Wanapum Lower Hydropower is an Roza Lower Granite Missoula Mossyrock Monumental exceptionally valuable c Mayfield Priest S

n Dworshak i Rapids Ice Harbor Little a source of this capability: k Chandler Goose e f Swift Ariel R i Yale ver iv „„ Dam operators can Bonneville ia Ri e Columb r c McNary start, stop, increase or Portland John Day a r The decrease generation by e v Dalles ORE GON i Hells P hundreds of megawatts R e t t Big Cliff in seconds to minutes e Federal dam on automatic generation control Oxbow

m a Pelton Brownlee l Federal Detroitdam (if water is available). l i Round Butte Non-federalGreen dam Peter Cascade WY W Foster Columbia RiverCougar Gorge wind projects „„ Natural gas-fired Dexter Lookout Point Black Canyon combustion turbines Automatic Generation Control allows federal hydro operators to use the lower Snake Lucky Hills Creek are next fastest in their River dams to meet loads minute-to-minute while using the Columbia River damsBo istoe Peak Palisades Owyhee r Andersonability to quickly e support wind power. There are 31 federal dams in the Columbia Basin; the 10 largest iv R have AGC capability. increase or decrease e ak Swan Sn Falls Upoutput.per C J Falls American Strike Milner Falls 3 Minidoka „„ Thermal plants such as nuclear and coal-fired Because the region is already planning to achieve all generation take many minutes or hours to achieve cost-effective conservation and renewables, the similar ramps. Council found that replacing the four Snake River dams would require “1,103 aMW of energy with 437 aMW To maintain system reliability with more than 2,800 MW coming from carbon producing resources, not including of wind power in its grid, BPA now adjusts hydro increased imports that would also most likely come generation up or down by as much as hundreds of from carbon producing resources.”3 megawatts within individual hours to counterbalance unexpected increases or decreases in wind generation. The Council’s analysis also found that replacing the BPA generally makes these within-hour adjustments at power from the four lower Snake River dams would mainstem Columbia River dams while using the lower cost an estimated $530 million annually, resulting in an Snake River dams to help meet loads. increase in BPA’s wholesale power rate of 24 percent to 29 percent.4 The four lower Snake River dams carry roughly one- quarter of BPA’s operating reserves, capacity that utilities are required to have available to meet Without the flexibility and operating unexpected hourly changes in load. Without the flexibility and operating reserves that these dams reserves that these dams supply, supply, BPA would lose a substantial amount of its BPA would lose a significant ability to deliver energy to the power system. amount of its ability to deliver wind Costs to replace the output of energy to the power system. the lower Snake River dams As described in the Council’s Sixth Power Plan, the region can meet 85 percent of its expected load growth Similarly, BPA’s own analysis found that replacing the with cost-effective conservation (estimated at 5,900 aMW power from the four lower Snake River dams would over 20 years). In addition, the Council’s plan estimates cost the Northwest $444 million to $501 million the region can add 4,500 MW of new wind power. Some (net of the dams’ annual $38 million operation and natural gas resources will be needed to meet remaining maintenance costs), increasing BPA’s wholesale power load growth and to provide capacity and flexibility for rates by roughly 25 percent. integrating wind generation and meeting peak loads. Conclusion The four lower Snake River dams are important to the Northwest’s power needs, provide important support for the transmission system and help keep our system low in carbon emissions.

3 Northwest Power and Conservation Council, “Sixth Northwest Power Plan” (Feb. 2010), Chapter 10. Little Goose Dam — capacity 810 MW, energized 1970 4 Ibid.

Bonneville Power Administration DOE/BP-4148 l March 2010